And as Adam Smith pointed out, it is there, and visible. It can't be hidden, can't be spirited out of town or offshore during the dark of night. You don't even need to know who it is that owns it; as long as they pay their land value tax, they can remain anonymous.

You might search for the term "unearned increment." It was a common expression to point out what people who reaped but did not sow receive due to our failure to collect the economic rent.

One person's unearned increment is another's — and likely many others' — lost birthright. Who is entitled to it? All of us! How do we implement this? Land value taxation.